This invention relates generally, as indicated, to a water filtration system for aquariums, and more particularly, to a system for providing auxiliary filtration of the water passing through an undergravel filter within an aquarium.
Filters of various types are commonly used for filtering out impurities from the water in an aquarium which might otherwise be injurious or fatal to the aquatic life in the aquarium. One such filter consists of a canister filled with a suitable filter media, with openings in the sides of the canister through which water is continuously drawn by a submersible electric pump connected to the canister outlet for recirculation in the aquarium.
Another filter in widespread use is an undergravel filter having a lift tube extending upwardly therefrom containing an air lift device or connected to a water pump which causes the water to flow through the undergravel filter and out through the lift tube for recirculation in the aquarium. If sized properly, such an undergravel filter should be fairly effective in keeping impurities in the water at a safe level. However, it would be advantageous to provide for additional filtering of the water as it is circulated through an undergravel filter.